impromptu (n.)
- ad-lib
- arrangement
- cadenza
- extemporization
- flourish
- improvisation
- interpolation
- lick
- makeshift
- measure
- precipitate
- quick
- riff
- snap
- stopgap
- unready
- vamp
impromptu (adv.)
impromptu (adj.)
- ad-lib
- extemporaneous
- extemporary
- extempore
- haphazard
- hasty
- improvised
- jury-rigged
- lick
- makeshift
- off-the-cuff
- offhand
- precipitate
- quick
- rough-and-ready
- surprised
- uncontrived
- unhatched
- unmade
- unorganized
- unplanned
- unpremeditated
- unprepared
- unready
- unrehearsed
- unstudied
